The edge effects of 33 gaps were studied in Cunninghamia lanceolata plantation in Ancaoxia, Fujian Province. China, using the Shannon-Wiener index and Simpson index. The two indexes illustrate the species diversity and the ecological dominance, respectively. The gap edge effect index based on the species diversity (ED) was 0.6-1.8 and that based on the ecological dominance (EC) was 0.3-3.4. Human disturbance and nature disturbance had the same effect on the edge effects of the gaps, and ED reached the peak in the gaps of 250-300 m2 in size. The edge effects of the gaps were suitable for species diversity in the edge zone.